The present invention generally relates to a fastening device, and particularly to a fastening device for releaseably attaching a heat sink to a chipset package.
A heat sink is used with an electronic device package for transferring heat from the device contained in the device package and rapidly dissipating the heat to the atmosphere by conduction, convection and/or radiation. Various means have been used to attach heat sinks in intimate thermal contact with the electronic device package. Conventional fastening devices are disclosed in U.S. Pat. Nos. 4,712,159; 5,436,798; and 5,602,719. However, such fastening devices have large dimensions and complex structures requiring a considerable amount of material and complicating assembly. In order to facilitate an automatic assembly, a product or an element thereof should have a simple structure. The above fastening devices do not meet such a requirement and can not be conveniently manufactured automatically.
FIG. 1 shows a chipset package 600 mounted on a PCB 500 (Printed Circuit Board), a heat sink 200, and a pair of conventional fastening devices 100. The heat sink 200 includes a pair of wings 202 outwardly extending therefrom. An aperture 204 is defined through each wing 202 in alignment with a hole 502 defined in the PCB 500 The fastening device 100 includes a compression spring 400 and a fastener 300. The fasteners 300 extend through the springs 400, the apertures 204 and the holes 502 to attach the heat sink 200 to the PCB 500. The springs 400 provide elastic engagement among the fasteners 300, the heat sink 200 and the PCB 500. However, the fastening device 100 includes two elements thereby complicating assembly and hindering automatic manufacture.
Therefore, a fastening device which is unitarily made is desired.